So much talent, so much versatility, so many different skills.
This is the long game to finding the best trio.
"It has been a year for us to try and chuck a couple of new guys in," All Blacks assistant coach Ian Foster said. "We've put Jordie in there. Rieko is a bit of a given but he's still growing his game too. Ben is so competent in any of those three positions so it's been a matter of working that around as we go through.
"Like everything we've got a plan and it's falling into place but we're certainly open-minded."
While he has featured there previously, the value the All Blacks hold in McKenzie from the back as a dual playmaking option arrived late this season, his first start at 15 coming two weeks ago in Yokohama.
For now, the All Blacks like the way it relieves pressure on Beauden Barrett to run the ship alone, and also allows the option of having three playmakers on the field at the same time once Richie Mo'unga is injected.
"There were a lot of decisions Beauden had to make by himself and that's not the way we like to play.
"It's not just about a 15. It's making sure we've got strong voices out there and more than one clear decision maker. We've made strides there but then there's testing accuracy when you get exposed to different defence systems which is our challenge now."
The other element involved in selecting the best trio is the World Cup destination.
Japan, in theory, will produce hot, fast pitches and will, therefore, require teams to be comfortable playing on top of the ground.
"Whether it's going to suit a game purely based on kicking and territory is a little bit to be seen. We learnt a lot in Japan the last two weeks about the surfaces, the grounds, the climate. It's going to be a very different World Cup."
Whoever starts this weekend will be well aware the goal posts are about to shift from Super and the Rugby Championship, with high ball season commencing at Twickenham.
The All Blacks expect to be repeatedly tested, by both England and Ireland, with accurate box kicks and well placed bombs.
That's the next chapter of the 2018 book for the back three.
"Then we'll sit back and say where did we end up?"